Frustrating slab


rfcomm2k
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I designed a pole barn to match as close as possible an existing structure (28 x 38 size, 15' 6" posts set on 48" deep footings, then concrete slab poured to the top of the footings, roof trusses 32' wide resting on double 2x12 beams on outer posts and on middle posts. Peak is 26' 10") Existing structure is shown on attaché plan with blue hatch.

 

I had to manually add the middle posts, footings, and double beam because the software seems to think a 28' span is perfectly acceptable for 2x6 truss construction. (sarcasm)

 

After building was as close to existing I then added 2 additions. First was easy, simply drag the west wall to create a new bay number 4, add another post and footing manually, and extend the beam.

 

The rear (North) addition was a challenge because the roofline was extended to reach the outer wall but the pitch was maintained so new rear wall was only 9' high instead of 15'6".

 

I then looked at a camera view of the east side and saw that a number of problems existed:

 

1. The new side walls for addition have the top "beam" extending past the roofline like a cantilever

 

2. The existing slab no longer lined up with the top of the footings

 

3. A stem wall now exists where there should not be one (posts rest on footings, slab rests on gravel base, no stem wall in existing structure.

 

4. Slab in rear entry and bathroom seems to be at correct height, at least visually, but rest of rear addition and other areas the slab is wrong (# 2 above)

 

I have opened the room DBX for existing area and tried to edit the structure settings by changing stem wall to 0" or to -24 5/8". It lets me change it but when I click OK it reverts back to the previous settings.

 

Any suggestions?

 

What if I were to recreate the walls as 2x6 construction instead of post and rail, and then manually place columns. Will these columns be visible in the plan AND perspective views?

 

Will this then correct the problem stated in #1 above?

 

 

 

 

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Yep post pictures or the plan same as last time..... 

 

HD titles don't do any Engineering , (nor Chief for that Matter) , it drew 2x6 Trusses cos that's what you specified.....  but 28' isn't that far the average double garage is 22' so a 25' truss with the 18" overhangs is pretty normal.....

 

M.

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I looked at your old plan I have and if you left the Roof at 8/12 and the room at 9' the roof will be incorrect , even though it looks like it works as HD has just shifted the whole roof over to work , ie the ridge is no longer centered on the original barn.  at 9' in the office the outer wall of the office needs to be set to 5/12 pitch and the upper pitch set at 8/12 starting 120" in from the Baseline. (see pic below)

 

The foundation issue is because in the original barn you used a slab for the floor , per the tutorial , so there is no foundation built , so when you add walls to the office area it has tried to add the default foundation, a stemwall ......delete the slab and foundation if needed  and rebuild the foundation as a monolithic Slab 6" thick. it will look thicker in 3d as HD adds a footing automatically (pic 1) , but you can turn off the footing in the foundation wall DBX so you have just the slab per Pic2. 

 

M

 

post-25-0-77030100-1410153232_thumb.jpg

 

post-25-0-49827100-1410153244_thumb.jpg

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OK, I decided to start over from the beginning. Drew the slab first, then the walls. Then tried to modify the roof so that the trusses rest on top of the beams instead of overhanging them as seen in the attached pict.

 

Also, tried to add concrete piers under the posts. First one went OK but all the others would alter the posts by adding one or more on either side of pier. So I deleted them.

 

I have tried the online help but could not see where I am going wrong.

 

 

 

 

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There is a "Raise off Top Plate" input box in the build roof dialog that controls roof height relative to the top plate. The way the truss tool works is that it manually fills the space between the flat ceiling and the bottom of the roof planes so it is imcumbent upon you to tell (set) that height as above and then the truss tool will then fill the spaces you create.

 

In terms of posts and footings, you must manually edit those to your purposes using manual tools. The software is merely a mechanical device that must be led-controlled to a specific result and that control must come from you (not the software).

 

DJP

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There is a "Raise off Top Plate" input box in the build roof dialog that controls roof height relative to the top plate. The way the truss tool works is that it manually fills the space between the flat ceiling and the bottom of the roof planes so it is imcumbent upon you to tell (set) that height as above and then the truss tool will then fill the spaces you create.

 

Thank you David, that was a big help. However, I specified trusses in the Build Roof DBX but all it did was show roof rafters, no trusses. I had to manually build trusses and then align them with the existing rafters. This presented the problem in that the truss now over rides the "Raise off Top Plate" info.

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Thank you David, that was a big help. However, I specified trusses in the Build Roof DBX but all it did was show roof rafters, no trusses. I had to manually build trusses and then align them with the existing rafters.

That is the way it is designed to be used: you make your presettings, build roofs, then manually build trusses and then and only then build framing. The auto-framing then frames to the trusses that should be in place. That procedure is laid out, step by step in the Reference Manual found under the "Help" menu. I realize that it is many pages but the way to address that document is a little at a time followed by practice on what was studied. It is searchable and so you can persue your interests as opposed to reading it in sequence.

 

DJP

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I am not sure what was wrong with the plan you had ? curious why you started again since all looks okay in the plan you posted in the other thread ,(see my post above )

 

Trusses must always be drawn manually and they automatically replace the rafters assuming the same framing layout/spacing......

 

M.

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